Tabcorp chief executive David Attenborough has described suggestions that it should demerge its booming lotteries business as “total nonsense”, saying proponents underestimated the benefits the lotteries business got from the diversified group.

But major shareholder Perpetual, which owns 5.9 per cent of the company, insists a spin-off should be considered, arguing the struggles of Tabcorp's smaller wagering division were preventing the lotteries division's infrastructure-like qualities from being recognised by the market.